Geração de hidrogênio por eletrólise da água utilizando energia solar fotovoltaica

Abstract

In view of the Hydrogen Economy and its endless possibilities, this work studies the hydrogen production using solar photovoltaic energy. With increasing global energy consumption, new methods of energy production have got to be taken into consideration, as hydrogen that it is an energy carrier with low environmental impact. On the other hand, fossil fuel reserves will not be able to meet this demand in the long term and its continuous use produces side effects such as pollution that threatens human health and greenhouse gases which are associated with climate change. For Brazilian energy context, electrolysis combined with renewable power source and fuel cell power generation would be a good basis to improve the distributed energy supply. It is proposed in this paper, to produce hydrogen by a direct coupling of a PV array with an experimental alkaline electrolyzer designed locally. It seeks to understand the inherent characteristics of the interaction of these energy forms, find the efficiencies of each step of the assembled system, as well as the global efficiency, acquiring a more precise notion and practice of the use of solar photovoltaic coupled with an electrolyzer. The experimental results showed that the transfer of energy from the PV array to the electrolyzer depends heavily on instant climatic conditions and how they are connected. The interdependence between variables was reproduced by the investigations, considering especially: current density, electric potential, solar irradiance, concentration of electrolyte, the electrode area and size of the electrolytic cell. The electrolyzer achieved an efficiency of 21%, approximately one-third of a commercial electrolyser efficiency. The overall efficiency (sol-hydrogen) was 2%. The present study gives subsidies to design an electrolyser-PV generator system based on a given electrolytic cell seeking low losses.

Evaluation of impurities in the Brazilian solar grade silicon and LeTID investigations in p-type multi-Si

“…Electricity is evolving to be the basis of the energy systems in this century, due to high technical efficiency, comparable low cost, and the availability of respective power-to-heat, power-to-water, power to-hydrocarbons and a directly or indirectly electrified transport sector. Hydrogen production via solar photovoltaicelectrolysis is a simple and feasible technology [6] and a common view for the decarbonization of the transport sector [7], [8], [9].…”

“…Source: Tine U. Naerland [34] The temperature and the carrier injection conditions can impact the degradation rate and the normalized defect density of the fast and the slow recombination centers [77]. Full dissociation of both fast and slow defects is observed after annealing at 200°C in the dark [6]. In Cz-Si, the metastable defects completely deactivate by applying simultaneous illumination and annealing at 65-210°C [130], [131].…”